Finding ways to alter the course of our fattening society is a national health priority. The next phase of this ongoing longitudinal study will be devoted to the study of obesity and other risk factors for the leading causes of death such as heart disease, type 2 diabetes, and cancer. The multiethnic Hawaii Personality and Health cohort offers an unprecedented opportunity to evaluate the processes by which childhood personality traits affect midlife health status, including obesity, as assessed by medical professionals 40-45 years later. The aims are to evaluate childhood personality traits as determinants of midlife overweight and obesity and other health risk factors, and to evaluate psychosocial mechanisms to explain these long- lasting influences of childhood traits. Gender and ethnic group differences in these processes will be examined, and stability of personality over 40+ years evaluated. These aims will be accomplished by completing a further 375 baseline medical and psychological examinations to bring the total examined to 900, collecting further information by questionnaires, and integrating these new data with those already collected. The extraordinarily rich data set for the Hawaii cohort includes childhood personality assessments obtained 40+ years ago, contemporary adult data, status on numerous health risk factors assessed at the baseline medical exam conducted at midlife, and a frozen data bank of biological samples for future testing. Among the many expected contributions, this research will advance understanding of the processes by which childhood personality traits have long-term effects on obesity and health;the influence of prior adverse experiences on adult obesity and health;why educational attainment affects obesity and health;ethnic differences in life-course pathways to midlife obesity and health status among Japanese Americans, Native Hawaiians, and Caucasians;and gender differences in these pathways. Consistent with the mission of NIA, this project will contribute to efforts to improve the health and well-being of older Americans by identifying new childhood risk factors for adult ill-health and obesity risk and thus opening up new possibilities for early preventive interventions. This project will also contribute to the study of ethnicity-based health disparities, which is an NIH-wide priority. This research exemplifies a new approach to the prevention of chronic diseases of middle age made possible by life span studies such as this. A significant practical outcome of this project is the potential for targeting children at risk of becoming obese by midlife. Long-term weight loss is notoriously hard for adults to achieve, in part because it requires major changes in life-long behavioral patterns. Intervening much earlier to prevent weight gain by deflecting high-risk children from life pathways leading to adult obesity may be a more successful strategy.